NEW PN STRUCTURE FORMED BY IMPROVED DOPING METHODS TO SIMPLIFY MANUFACTURING PROCESS OF DIODES FOR SOLAR CELLS

摘要

A method for doping a semiconductor substrate is disclosed wherein a layer of a first conductivity type is first formed followed by forming a blocking layer with an open area. An etch process is performed through the open area to remove the layer of the first conductivity type to exposed the top surface of the semiconductor substrate. Dopant ions are introduced to form a dopant region of a second conductivity type on the beneath the top surface of the semiconductor substrate wherein the dopant region of the second conductivity type is not in contact with the dopant layer of the first conductivity type that is not etched off thus forming a PN structure to form diodes for the interdigitated back contact photovoltaic cells. Since the ion doping processes are self-aligned, the mask requirements are minimized and the production cost for solar cells are reduced.

主权项

1. A method for manufacturing a PN structure on a semiconductor substrate of a first conductivity type comprising:
doping a top layer on a first surface of the semiconductor substrate as a first conductivity type layer; covering the first conductivity layer with a blocking layer; etching a doping opening through the blocking layer and removing the first conductivity type layer beneath the doping opening to expose an opening area on the first surface of the semiconductor substrate and leaving an un-etched portion of the first conductivity layer; and doping the open area on the first surface of the semiconductor substrate with dopant ions of a second conductivity type to form a second conductivity region by keeping a distance between the second conductivity type region and the un-etched portion of the first conductivity layer to constitute the PN structure.